Why does a sub-class class of a class have to be static in order to initialize the sub-class in the
- by Alex
So, the question is more or less as I wrote.
I understand that it's probably not clear at all so I'll give an example.
I have class Tree and in it there is the class Node, and the empty constructor of Tree is written:
public class RBTree {
private RBNode head;
public RBTree(RBNode head,RBTree leftT,RBTree rightT){
this.head=head;
this.head.leftT.head.father = head;
this.head.rightT.head.father = head;
}
public RBTree(RBNode head){
this(head,new RBTree(),new RBTree());
}
public RBTree(){
this(new RBNode(),null,null);
}
public class RBNode{
private int value;
private boolean isBlack;
private RBNode father;
private RBTree leftT;
private RBTree rightT;
}
}
Eclipse gives me the error: "No enclosing instance of type RBTree is available due to some intermediate constructor invocation" for the "new RBTree()" in the empty constructor.
However, if I change the RBNode to be a static class, there is no problem.
So why is it working when the class is static.
BTW, I found an easy solution for the cunstructor:
public RBTree(){
this.head = new RBNode();
}
So, I have no idea what is the problem in the first piece of code.
